Ultrasound and phakometry measurements of the primate eye Technical report, Aug. 1965

Ultrasonic testing and phakometry measurements of primate ey

Computer automation of ultrasonic testing

Report describes a prototype computer-automated ultrasonic system developed for the inspection of weldments. This system can be operated in three modes: manual, automatic, and computer-controlled. In the computer-controlled mode, the system will automatically acquire, process, analyze, store, and display ultrasonic inspection data in real-time. Flaw size (in cross-section), location (depth), and type (porosity-like or crack-like) can be automatically discerned and displayed. The results and pertinent parameters are recorded

Ballpoint probe gives optimum results in ultrasonic testing

Ballpoint-type ultrasonic probe assembly focuses its beam precisely on the bond lines of a composite thin face sheet structure when testing for bond integrity. It can scan in any direction, and eliminate external couplant spray

On the scattering of torsional elastic waves from axisymmetric defects in coated pipes

This is the post-print version of the Article - Copyright @ 2012 ElsevierLong range ultrasonic testing is now a well established method for examining in-service degradation in pipelines. In order to protect pipelines from the surrounding environment it is common for viscoelastic coatings to be applied to the outer surface. These coatings are, however, known to impact on the ability of long range ultrasonic techniques to locate degradation, or defects, within a coated pipe. The coating dissipates sound energy travelling along the pipe, attenuating both the incident and reflected signals making responses from defects difficult to detect. This article aims to investigate the influence of a viscoelastic coating on the ability of long range ultrasonic testing to detect a defect in an axisymmetric pipe. The article focuses on understanding the behaviour of the fundamental torsional mode and quantifying the effect of bitumen coatings on reflection coefficients generated by axisymmetric defects. Reflection coefficients are measured experimentally for coated and uncoated pipes and compared to theoretical predictions generated using numerical mode matching and a hybrid finite element technique. Good agreement between prediction and measurement is observed for uncoated pipes, and it is shown that the theoretical methods presented here are fast and efficient making them suitable for studying long pipe runs. However, when studying coated pipes agreement between theory and prediction is observed to be poor for predictions based on those bulk acoustic properties currently reported in the literature for bitumen. Good agreement is observed only after conducting a parametric study to identify more appropriate values for the bulk acoustic properties. Furthermore, the reflection coefficients obtained for the fundamental torsional mode in a coated pipe show that significant sound attenuation is present over relatively short lengths of coating, thus quantifying those problems commonly encountered with the use of long range ultrasonic testing on coated pipes in the field

Разработка методики ультразвукового контроля неравномерности распределения гидрида в титановом сплаве ВТ1-0

This paper is devoted to investigation of development of ultrasonic testing method for the uneven distribution of hydrides in titanium alloys VT1-0. The linear prediction method(LPC) is used to determine hydrides in titanium alloy VT1-0.X-ray diffraction (XRD) is used to confirm the results of ultrasonic testing

Effects of specimen resonances on acoustic-ultrasonic testing

The effects of specimen resonances on acoustic ultrasonic (AU) nondestructive testing were investigated. Selected resonant frequencies and the corresponding normal mode nodal patterns of the aluminum block are measured up to 75.64 kHz. Prominent peaks in the pencil lead fracture and sphere impact spectra from the two transducer locations corresponded exactly to resonant frequencies of the block. It is established that the resonant frequencies of the block dominated the spectral content of the output signal. The spectral content of the output signals is further influenced by the transducer location relative to the resonant frequency nodal lines. Implications of the results are discussed in relation to AU parameters and measurements

AUTOMATION OF NON-DESTRUCTIVE TESTING TECHINIQUES USED FOR FINDING DEFECTS

This master thesis focuses on the automation and fusion of non-destructive testing methods. The research includes the fusion of non-destructive testing methods done with infrared micro-bolometer and ultrasonic transducers. A control system which utilized mechanical, electrical, electronic systems and computer aided technologies was developed. Conveyor belt system, PLC (programmable logic controller), XYZ mechanism and different sensors were utilized to automate the process of capturing images and a communication link was set up between thermal camera and system that controls the ultrasonic testing apparatus, to integrate the two techniques. The test results from the thermal camera were utilized in ultrasonic testing. It is observed that in thermal imaging as well as in ultrasonic testing, the results after automating the process were promising and helped to make testing easier. In thermal imaging we were able to find defects at different moving speeds of the sample and at different distances between sample and heating source, from which we understood the relation between different testing conditions and were able to predict the best factory conditions for testing and using ultrasonic testing method the nature of the defects were found in more accurate and faster way

Ultrasonic testing of composite materials

В статье рассмотрен теневой метод контроля композитов. Исследованы характеристикитеневого метод контроля при использовании линейных решеток. Рассчитана направленность для одиночного излучателя и линейных антенных решеток с различным количеством преобразователей.The article deals with the through-transmission testing method for Composites. The characteristics of the through-transmission testing method are investigated using linear arrays. The direction for a single transmitter and linear antenna arrays with a different number of transducers is calculated

A review of miniaturised Non-Destructive Testing technologies for in-situ inspections

Non-destructive testing (NDT) techniques have become attractive trends of product manufacturing, installation and post-maintenance in the aerospace, automotive and manufacturing industry, because of its benefits such as cost saving, easy to use and high efficiency etc. With the industrial products becoming large-scale, high integration and complication, developing the NDT miniaturisation technique for in-situ inspections is highly demanded and becoming an inevitable trend. However, in-situ inspection using NDT have been limited by a number of factors, such as the heavy weight, large size or complex structure etc. This paper aims to systematically identify and analyse the current state-of-the-art of NDT miniaturisation techniques in research and innovation, and discuss the challenge and prospect of miniaturisation of the commonly used NDT techniques

RELATIONSHIP OF DEW POINT AND AMBIENT TEMPERATURE VARIATION ON WELD QUALITY

This investigation deals with the study of the effect of environmental parameters viz dew point temperature, relative humidity, ambient air temperature, and job surface temperature on robotic MAG (Metal active gas) welded joint quality. Weld samples taken were mass manufacturing welded structures of a heavy-large scale industry, which were further subjected to semi-automatic ultrasonic testing to assess defects within welded joints. The trend of defects observed and recorded after ultrasonic testing of weld joints was co-related with the trend of atmospheric parameters for a span of four years to establish a linear empirical relationship. It has been established that variations in atmospheric parameters resulted in variations in the trend of weld defects. These variations were studied to get the empirical relationship to establish the effect of variation in atmospheric parameters on weld quality or defects in joints. It has been observed that whenever there was a drop in the "difference in ambient air temperature & dew point temperature, especially less than 5", a drop in ultrasonic testing straight pass % was observed than the average value